JPH0270195A - Electronic noise silencing system - Google Patents

Electronic noise silencing system

Info

Publication number
JPH0270195A
JPH0270195A JP63223028A JP22302888A JPH0270195A JP H0270195 A JPH0270195 A JP H0270195A JP 63223028 A JP63223028 A JP 63223028A JP 22302888 A JP22302888 A JP 22302888A JP H0270195 A JPH0270195 A JP H0270195A
Authority
JP
Japan
Prior art keywords
sound wave
signal
conversion means
transfer function
digital filter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP63223028A
Other languages
Japanese (ja)
Other versions
JP2598483B2 (en
Inventor
Minoru Takahashi
稔 高橋
Tanetoshi Miura
三浦　種敏
Haruo Hamada
晴夫 浜田
Hideki Hyodo
兵頭　英樹
Ryusuke Gotoda
龍介 後藤田
Yasushi Yoshimura
康史 吉村
Taku Kuribayashi
栗林　卓
Akio Akasaka
赤坂　章男
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Plant Technologies Ltd
Original Assignee
Hitachi Plant Technologies Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Plant Technologies Ltd filed Critical Hitachi Plant Technologies Ltd
Priority to JP63223028A priority Critical patent/JP2598483B2/en
Priority to US07/313,475 priority patent/US5018202A/en
Priority to GB8904719A priority patent/GB2222501B/en
Priority to DE3908881A priority patent/DE3908881C2/en
Priority to IT8967207A priority patent/IT1232050B/en
Priority to FR8903869A priority patent/FR2636189B1/en
Publication of JPH0270195A publication Critical patent/JPH0270195A/en
Application granted granted Critical
Publication of JP2598483B2 publication Critical patent/JP2598483B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17821—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the input signals only
    • G10K11/17823—Reference signals, e.g. ambient acoustic environment
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17813—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
    • G10K11/17815—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the reference signals and the error signals, i.e. primary path
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17813—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms
    • G10K11/17817—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the acoustic paths, e.g. estimating, calibrating or testing of transfer functions or cross-terms between the output signals and the error signals, i.e. secondary path
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17821—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the input signals only
    • G10K11/17825—Error signals
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17853—Methods, e.g. algorithms; Devices of the filter
    • G10K11/17854—Methods, e.g. algorithms; Devices of the filter the filter being an adaptive filter
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17857—Geometric disposition, e.g. placement of microphones
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1787—General system configurations
    • G10K11/17879—General system configurations using both a reference signal and an error signal
    • G10K11/17881—General system configurations using both a reference signal and an error signal the reference signal being an acoustic signal, e.g. recorded with a microphone
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3045—Multiple acoustic inputs, single acoustic output
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3049—Random noise used, e.g. in model identification
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/50—Miscellaneous
    • G10K2210/508—Reviews on ANC in general, e.g. literature

Abstract

PURPOSE:To obtain the electronic noise silencing system of high sound silencing effect by generating the sound wave of the same sound pressure in opposite phase by performing adaptive control for the propagated sound wave from a noise source by computer system with a built-in digital filter. CONSTITUTION:In the propagation path 1 of the sound wave, sensor microphones M1, M2 to detect the propagated sound wave from the noise source are arranged respectively at the upstream side and the downstream side of the standard of a speaker S as an additional sound source. At an adding point 20, the output signals of the microphone M1 and a sound feedback controlling digital filter 22 are added together in the opposite phase. The output signal of the adding point 20 is inputted to an adaptive digital filter 2 and a controller part 10. The output signal of the microphone M2 is inputted as an error signal E to the controller part 10. Thus, the propagated sound wave from the noise source can be effectively eliminated at the position of the microphone M2.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は電子消音ンステムに係り、特にディジクルフィ
ルタを組み込んだコンピュータシステムにより適応制御
を行うことにより、管路等の伝搬通路内に発生する非定
常的騒音の消音を可能とした電子消音システムの改良に
関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electronic sound damping system, and in particular, by performing adaptive control using a computer system incorporating a digital filter, noise generation in a propagation path such as a pipeline can be suppressed. This paper relates to improvements to electronic silencing systems that are capable of silencing non-stationary noise.

〔従来の技術〕[Conventional technology]

管内騒音に対する消音を管構造による干渉や管に内貼り
した多孔質材による吸音等の現象を利用して行う受動型
消音器は広く実用に供されているが、消音器のサイズ、
圧力損失等の点でその改善に対する要求が多い。Passive silencers are widely used in practical use, and are used to muffle noise inside pipes by utilizing phenomena such as interference by the pipe structure and sound absorption by porous materials lined inside the pipe. However, the size of the silencer,
There are many demands for improvement in terms of pressure loss, etc.

一方、これに対して管内騒音を消音するもう一つの方法
として古くから提案されていた能動型消音器、即ち音源
から伝搬してきた騒音に対し、同一音圧、逆位相の付加
音を放射し、音波干渉により消音効果を強制的に生じさ
せる電子消音ンステムが着目されつつあり、電子デバイ
ス、信号処理技術等の急速な発達に伴って、最近様々な
観点からの研究成果が次々を発表されている。On the other hand, an active muffler, which has been proposed for a long time as another method of muffling pipe noise, is a system that emits additional sound of the same sound pressure and opposite phase to the noise propagating from the sound source. Electronic silencing systems that forcibly create a silencing effect through sound wave interference are attracting attention, and with the rapid development of electronic devices, signal processing technology, etc., research results from various perspectives have recently been published one after another. .

しかしながら、解決すべき多くの問題が山積しており、
現在ではまだ本格的な実用段階には至っていない。However, there are many problems that need to be solved.
At present, it has not yet reached the stage of full-scale practical use.

電子消音システムを実用化するだめの技術課題はその制
御系設計の基礎となるモデルの構築にあり、そのモデル
は下記の点に対応できることが要求される。先ず第１の
問題は連続スペクトル騒音の消音用フィルタを形成する
ことである。即ち変圧器騒音やコンプレッサ騒音のよう
な離散スペクトル騒音のみならず自動車騒音や気流騒音
のような連続スペクトル騒音に対しても付加音を発生さ
せることができれば電子消音システムの用途が更に拡大
する。この実現に当たっては任意の振幅特性と位相特性
が得られるフィルタが必要となる。The technical challenge in putting an electronic silencing system into practical use lies in the construction of a model that serves as the basis for its control system design, and the model is required to be able to accommodate the following points. The first problem is to form a continuous spectrum noise filter. That is, if additional sound can be generated not only for discrete spectrum noise such as transformer noise and compressor noise, but also for continuous spectrum noise such as automobile noise and airflow noise, the applications of electronic silencing systems will be further expanded. To realize this, a filter that can obtain arbitrary amplitude characteristics and phase characteristics is required.

第２の問題はセンサマイクロフォンに対する付加音の帰
還を防止しなければならないという点である。即ち電子
消音システムでは音波が伝搬する伝搬通路内における騒
音源と付加音源との間にセンサマイクロフォンが設置さ
れ、これにより検出した音から何等かの手段で騒音源か
らの伝搬音波を打ち消す為の音波を放射する付加音源を
駆動するための電気信号を作成することが必要となる。The second problem is that it is necessary to prevent additional sound from returning to the sensor microphone. In other words, in an electronic silencing system, a sensor microphone is installed between a noise source and an additional sound source in a propagation path through which sound waves propagate, and from the detected sound, a sound wave is generated by some means to cancel out the sound waves propagating from the noise source. It is necessary to create an electrical signal to drive an additional sound source that emits .

この場合に付加音源から放射される音波はセンサマイク
ロフォンにも捕らえられるために結局、付加音源とセン
サマイクロフォンとの間に音響的フィードバック系が形
成されるのでこれに対する対策が必須となる。特に電子
消音システムを小型化し且つダクト等の管路の任意の位
置に取付は可能に構成するためにはセンサマイクロフォ
ント付加音源とを近接せざるを得ない為にこの音響的フ
ィードバックの影響は大きく、これに対する対策が重要
となる。In this case, since the sound waves emitted from the additional sound source are also captured by the sensor microphone, an acoustic feedback system is formed between the additional sound source and the sensor microphone, and countermeasures against this are essential. In particular, in order to miniaturize the electronic silencing system and make it possible to install it at any position in a conduit such as a duct, it is necessary to place the sensor microfont attached to the sound source in close proximity, so the influence of this acoustic feedback is large. , countermeasures against this are important.

更に第３の問題は電子消音システムに用いられるマイク
ロフォン、スピーカ等の電気音響変換器の特性補正を可
能にすることである。即ち電子消音ンステムの制御機能
を安定化させるためには制御系に電気音響変換器の微小
な特性劣化を補正する機能を持たせることが必須であり
、この問題も解決しなければならない。A third problem is to make it possible to correct the characteristics of electroacoustic transducers such as microphones and speakers used in electronic silencing systems. That is, in order to stabilize the control function of the electronic silencing system, it is essential to provide the control system with a function of correcting minute characteristic deterioration of the electroacoustic transducer, and this problem must also be solved.

これに対して我々は既に上記問題点に対応できる電子消
音システムについてのモデルを解明し、提案している（
特願昭６０−１３９２９３、特願昭６０−１３９２９４
、特願昭６１−７１１５、特願昭６２−１４８２５４）
。In response, we have already elucidated and proposed a model for an electronic silencing system that can address the above problems (
Patent application 1986-139293, patent application 1986-139294
, patent application No. 61-7115, patent application No. 62-148254)
.

我々が提案した電子消音システムでは上記第３の問題に
対応できるように付加音源に与える電気信号を作成する
ためのディジクルフィルタノ特性を適応制御することに
より音波の伝搬通路（例えばダクト）の伝搬特性の変化
及び制御系（付加音源としてのスピーカ、センサとして
のマイクロフォン等を含む）の特性変化に対応可能とし
ている。In order to deal with the third problem mentioned above, the electronic silencing system that we have proposed uses adaptive control of the dicicle filter characteristics to create an electrical signal to be applied to the additional sound source. It is possible to respond to changes in characteristics and changes in characteristics of the control system (including speakers as additional sound sources, microphones as sensors, etc.).

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

第１図に二つのセンサマイクロフォンＭ　ｌ、Ｍ２を備
えた単極音源方式の適応型電子消音システムの基本構成
を示す。FIG. 1 shows the basic configuration of a single-pole sound source type adaptive electronic muffling system equipped with two sensor microphones M1 and M2.

この構成では下流側のセンサマイクロフォンＭ２の出力
をエラー信号として用いている。基本的な動作としては
、ディジタルフィルタ２０入力Ｘとセンサマイクロフォ
ンＭ２の出力Ｅの情報からＥのエネルギーが何等かの評
価基準のもとて最小となるようにディジタルフィルタ２
の伝達関数を更新することである。In this configuration, the output of the downstream sensor microphone M2 is used as an error signal. The basic operation is based on the information of the digital filter 20 input X and the output E of the sensor microphone M2, so that the digital filter 2
The goal is to update the transfer function of .

さて、第１図に従って実際の電子消音システムをモデル
化すると第２図に示すようになる。第２図に示すモデル
では消音用スピーカ（付加音源）Ｓからセンサマイクロ
フォンＭ１に帰還される音波は加算点２０において電気
的に打ち消され、ディジタルフィルタ２には入力されな
いという仮定に基づいて構成されている。Now, when an actual electronic silencing system is modeled according to FIG. 1, it becomes as shown in FIG. 2. The model shown in FIG. 2 is constructed based on the assumption that the sound waves fed back from the silencing speaker (additional sound source) S to the sensor microphone M1 are electrically canceled at the addition point 20 and are not input to the digital filter 2. There is.

ここで重要なことは、ディジタルフィルタ２の出力から
エラー信号の加算点に至るまでにスピーカ、ダクト等の
伝送特性を表す時間遅延を伴った伝達関数りが存在する
ことである。What is important here is that a transfer function with a time delay exists from the output of the digital filter 2 to the addition point of the error signal, which represents the transmission characteristics of the speaker, duct, etc.

ところで、Ｖ　Ｓ　−Ｌ　Ｍ　Ｓ　（Ｖａｒｉａｂｌｅ
　Ｓｔｅｐ−ＬｅａｓｔＭｅａｎ　５ｑｕａｒｅ　）ア
ルゴリズムなど既存の適応制御アルゴリズムを適用する
ためには、適応型ディジタルフィルタの入力Ｘが明確に
定義されていることは勿論、その出力Ｙとエラー信号Ｅ
との関係が問題となってくる。ディジタルフィルタ２の
出力が決定された後、瞬時にエラー信号Ｅが観測可能な
システムの場合や、少なくともディジタルフィルタ２の
次の係数更新時までにエラー信号Ｅが確定しているシス
テムの場合には基本的には問題なく適用可能である。音
響信号を対象としたものとして、エコーキャンセラ用フ
ィルタなどはよい例であり、フィルタ出力Ｙはそのまま
エラー信号Ｅに反映されている。ところが、第１図に示
す電子消音システムのフィルタ出力はそのままの状態で
はＥに関係しておらず、スピーカの電気音響変換特性、
スピーカからマイクロフォンまでの伝送特性、空間での
音響信号の重畳（干渉）過程、マイクロフォンの音響電
気変換特性を経由してエラー信号Ｅが得られる。この伝
達関数りを考慮しないと消音効果は全く得られない。By the way, V S - L M S (Variable
In order to apply existing adaptive control algorithms such as the Step-LeastMean 5quare) algorithm, it is necessary to clearly define the input X of the adaptive digital filter, as well as its output Y and error signal E.
The relationship becomes a problem. In the case of a system in which the error signal E can be observed instantaneously after the output of the digital filter 2 is determined, or in the case of a system in which the error signal E is determined at least by the time of the next coefficient update of the digital filter 2, Basically, it can be applied without any problem. An echo canceller filter is a good example of a filter for acoustic signals, and the filter output Y is directly reflected in the error signal E. However, the filter output of the electronic silencing system shown in FIG.
The error signal E is obtained via the transmission characteristics from the speaker to the microphone, the superimposition (interference) process of acoustic signals in space, and the acoustoelectric conversion characteristics of the microphone. If this transfer function is not taken into consideration, no silencing effect can be obtained at all.

さらに、第８図に示すように先に出願した特許（特願昭
６２−１４８２５４　号）では音響フィードバックの抑
制はスピーカからマイクＭ１　及びスピーカかみマイク
Ｍ２　までの伝達関数が実用的に見て等しい場合のみに
有効である。殆どの直線的なダクト設備がこれを満足す
る。Furthermore, as shown in Fig. 8, in the previously filed patent (Japanese Patent Application No. 62-148254), acoustic feedback can be suppressed when the transfer functions from the speaker to the microphone M1 and the speaker-to-microphone M2 are practically equal. Valid only for Most straight ductwork meets this requirement.

しかしながら、曲りダクト部分にスピーカを取付は消音
器を構成する場合には本構成は十分な性能が発揮出来な
い。そこで、本発明を提案する。However, when a speaker is attached to a curved duct portion to form a muffler, this structure cannot exhibit sufficient performance. Therefore, the present invention is proposed.

音響的フィードバックの抑制はフィードバック系の伝達
関数を同定して行うため、任意のダクト形状に適用出来
る。さらには、３次元音場（屋外又は室内）における能
動的消音にも適用することが出来る。Since acoustic feedback is suppressed by identifying the transfer function of the feedback system, it can be applied to any duct shape. Furthermore, it can also be applied to active noise reduction in a three-dimensional sound field (outdoor or indoor).

本発明はこのような事情に鑑みてなされたものであり、
付加用音源から評価用マイクロフォンに至る伝送系の伝
達関数を考慮して適応制御を行い得ると共に、任意のダ
クト形状における音響的フィードバックの抑制を可能と
した電子消音システムを提供することを目的とするもの
である。The present invention was made in view of these circumstances, and
The purpose of the present invention is to provide an electronic silencing system that can perform adaptive control in consideration of the transfer function of the transmission system from the additional sound source to the evaluation microphone, and can suppress acoustic feedback in any duct shape. It is something.

〔問題点を解決するための手段〕[Means for solving problems]

本発明は上記目的を達成する為に、音波の伝搬通路内に
於ける騒音源からの伝搬音波に対して逆位相で且つ同一
音圧の音波を発生させ、前記伝相通路内の所定位置でそ
の音波干渉により消音を行う電子消音システムにおいて
、 前記伝搬通路内の前記所定位置より騒音源側に配設され
、該騒音源からの伝搬音波を検出し電気信号に変換する
第１の機械電気変換手段と、前記伝搬通路内に於ける第
１の機械電気変換手段の配設位置と前記所定位置との間
に設けられ騒音源からの伝搬音波を該所定位置において
打ち消すための音波を放射する電気機械変換手段と、該
電気機械変換手段の配設位置と前記所定位置との間又は
該所定位置に設けられ、該電気機械変換手段及び前記騒
音源からの伝搬音波を検出し電気信号に変換する第２の
機械電気変換手段と、前記第１の機械電気変換手段の出
力信号と電気機械変換手段に与える駆動信号を取込んで
両者の差を求める演算手段と、 該演算手段の出力信号を取り込み、与えられた伝達関数
に基づハで電子消音システムの消音量が最大にＩ；るよ
うに前記電気機械変換手段に与える駆動信号を作成する
駆動信号作成手段と、該駆動信号作成手段に付与すべき
伝達関数を決定し、該伝達関数を特定する為の制御パラ
メータを駆動信号作成手段に設定すると共に、伝搬通路
の伝搬特性の変化及び制御系の特性変化に応じて前記制
御パラメータを修正する制御手段とを有し、制御手段は
擬似信号を前記電気機械変換手段に出力して音波の伝搬
通路内に音波を放射し、第２の機械電気変換手段の出力
信号に基づいて該出力信号が最小となるように駆動信号
作成手段の出力端から第２の機＋ｔ１．電気変換手段に
至る音波の伝搬通路及び電気信号の伝送路を含む伝送系
の伝送特性を示す時間遅延を伴う伝達関数を特定し、該
特定された時間遅延を伴う伝達関数を考慮して所定の適
応アルゴリズムに基づいて前記駆動信号作成手段に付与
すべき伝達関数を決定することを特徴とするものである
。In order to achieve the above object, the present invention generates a sound wave having an opposite phase and the same sound pressure as the sound wave propagating from a noise source in a sound wave propagation path, and generates a sound wave at a predetermined position in the phase propagation path. In an electronic noise reduction system that performs noise reduction by sound wave interference, a first mechanical-electrical converter is disposed closer to the noise source than the predetermined position in the propagation path, and detects the propagating sound wave from the noise source and converts it into an electrical signal. a means for emitting sound waves for canceling propagating sound waves from the noise source at the predetermined position, provided between the location of the first electromechanical conversion means in the propagation path and the predetermined position; A mechanical conversion means, which is provided between the arrangement position of the electromechanical conversion means and the predetermined position or at the predetermined position, and detects a propagating sound wave from the electromechanical conversion means and the noise source and converts it into an electrical signal. a second mechanical-electrical converting means; a calculating means that takes in the output signal of the first mechanical-electrical converting means and a drive signal applied to the electro-mechanical converting means and calculates a difference between the two; and taking in the output signal of the calculating means. , drive signal generation means for generating a drive signal to be applied to the electromechanical conversion means so that the amount of silencing of the electronic noise reduction system is maximized based on a given transfer function; determining the transfer function to be used, setting control parameters for specifying the transfer function in the drive signal generating means, and modifying the control parameters in accordance with changes in the propagation characteristics of the propagation path and changes in the characteristics of the control system. and a control means, the control means outputs a pseudo signal to the electromechanical conversion means to radiate a sound wave into the sound wave propagation path, and the control means outputs a pseudo signal to the electromechanical conversion means to radiate a sound wave into the propagation path of the sound wave, and the output signal is adjusted based on the output signal of the second electromechanical conversion means. from the output end of the drive signal generating means to the second machine +t1. A transfer function with a time delay indicating the transmission characteristics of a transmission system including a sound wave propagation path and an electric signal transmission path leading to the electrical conversion means is specified, and a predetermined transfer function is determined in consideration of the specified transfer function with a time delay. The present invention is characterized in that a transfer function to be given to the drive signal generating means is determined based on an adaptive algorithm.

〔作用〕[Effect]

本発明に係る電子消音ンステムでは音波の伝搬通路内に
１疑似信号に基づく音波が付加音、原としての電気機械
変換手段より放射され、この音波に対して消音効果を評
価するための第２の機械電気変換手段の出力信号（エラ
ー信号）が最小となるように駆動信号作成手段の出力端
から第２の機械電気変換手段に至る音波の伝搬通路及び
電気信号の伝送路を含む伝送系の伝送特性を示す時間遅
延を伴う伝達関数が制御手段により特定される。In the electronic silencing system according to the present invention, a sound wave based on one pseudo signal is emitted from the electromechanical conversion means as an additional sound in the sound wave propagation path, and a second sound wave is used to evaluate the silencing effect on this sound wave. Transmission of a transmission system including a sound wave propagation path and an electrical signal transmission path from the output end of the drive signal generating means to the second mechanical-electrical conversion means so that the output signal (error signal) of the mechanical-electrical conversion means is minimized. A transfer function with a characteristic time delay is specified by the control means.

更に制御手段はこの特定された時間遅延を伴う伝達関数
を考慮して所定の適応アルゴリズムに基づいて前記駆動
信号作成手段に付与すべき伝達関数を決定する。Further, the control means takes into account the specified transfer function with time delay and determines the transfer function to be applied to the drive signal generation means based on a predetermined adaptive algorithm.

このように構成することにより消音効果の高い電子消音
システムを実現することができる。With this configuration, it is possible to realize an electronic muffling system with a high muffling effect.

〔実施例〕〔Example〕

以下、添付図面に従って本発明に係る電子消音ンステム
の好ましい実施例を詳説する。第１図には本発明が適用
される電子消音システムの基本構成が示されている。第
１図及び第２図については〔発明が解決しようとする問
題点〕の項で便宜上簡単に触れたが十分でないのでこの
項で再度、説明する。Hereinafter, preferred embodiments of the electronic silencing system according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows the basic configuration of an electronic silencing system to which the present invention is applied. Although FIGS. 1 and 2 have been briefly mentioned in the [Problems to be Solved by the Invention] section for convenience, they are not sufficient, so they will be explained again in this section.

第１図において音波の伝搬通路１内において騒音源から
の伝搬音波を検出する二つのセンサマイクロフォンＭｌ
’、Ｍ２が付加音源としてのスピーカＳを基準にしてそ
の上流側と下流側の位置に夫々設置されている。加算点
２０にはセンサマイクロフォンＭ１、音響フィードバッ
ク抑制用ディジタルフィルタ２２の出力信号が入力され
、ディジタルフィルタ２２の出力信号はセンサマイクロ
フォンＭ１の出力信号に対して逆位相で加算されるよう
になっている。In FIG. 1, two sensor microphones Ml detect propagating sound waves from a noise source in a sound wave propagation path 1.
', M2 are installed at positions upstream and downstream of the speaker S serving as an additional sound source, respectively. The output signals of the sensor microphone M1 and the digital filter 22 for suppressing acoustic feedback are inputted to the addition point 20, and the output signal of the digital filter 22 is added in opposite phase to the output signal of the sensor microphone M1. .

また加算点２０の出力信号は適応型ディジタルフィルタ
２及びコントローラ部１０に入力されるように構成され
ている。コントローラ部１０にはエラー信号Ｅとしてセ
ンサマイクロフォンＭ２の出力信号が入力されるように
なっている。Further, the output signal of the addition point 20 is configured to be input to the adaptive digital filter 2 and the controller section 10. An output signal from the sensor microphone M2 is input to the controller section 10 as an error signal E.

上記構成において、騒音源からの伝搬音波はセンサマイ
クロフォンＭ　１　、！ｖ１２により検出されると共に
、センサマイクロフォンＭ２の出力信号はエラー信号Ｅ
としてコントローラ部１０に入力される。In the above configuration, the propagating sound waves from the noise source are transmitted through the sensor microphone M 1 ,! v12, and the output signal of the sensor microphone M2 is an error signal E.
It is input to the controller section 10 as a.

加算点２０ではセンサマイクロフォンＭ１、音響フィー
ドバック抑制用ディジタルフィルタ２２の出力信号が互
いに逆位相で加算され、その加算出力Ｘはディジタルフ
ィルタ２及びコントローラ部１０に入力される。At the addition point 20, the output signals of the sensor microphone M1 and the acoustic feedback suppression digital filter 22 are added in opposite phases to each other, and the added output X is input to the digital filter 2 and the controller section 10.

コントローラ部１０はエラー信号Ｅが最小となるように
加算出力すなわち適応型でディジタルフィルタ入力Ｘ及
びエラー信号Ｅに基づいてディジタルフィルタ２に付与
すべき伝達関数を決定し、その伝達関数を特定するだめ
の制御パラメータであるフィルタ係数をディジタルフィ
ルタ２に与える。ディジタルフィルタ２では入力信号Ｘ
を与えられたフィルタ係数に基づいて所定の振幅、位相
特性の信号に変換処理する。このディジタルフィルタ２
の出力信号はＤ／Ａ変換されてセンサマイクロッオンＭ
２の位置において騒音源からの伝搬音波を消去するため
消音用音波を放射する付加音源としてのスピーカＳに出
力されるのである。このようにしてセンサマイクロフォ
ンＭ２の位置において騒音源からの伝搬音波は消去され
る。The controller unit 10 determines a transfer function to be applied to the digital filter 2 based on the digital filter input X and the error signal E using an additive output, that is, an adaptive type, so that the error signal E is minimized, and specifies the transfer function. A filter coefficient, which is a control parameter, is given to the digital filter 2. In digital filter 2, input signal
is converted into a signal with predetermined amplitude and phase characteristics based on the given filter coefficients. This digital filter 2
The output signal is D/A converted and sent to the sensor micro-on M.
At position 2, the sound is output to a speaker S as an additional sound source that emits a muffling sound wave to eliminate the propagating sound wave from the noise source. In this way, the propagating sound waves from the noise source are canceled at the position of the sensor microphone M2.

尚、スピーカＳからの消音用音波がセンサマイクロフォ
ンＭ１により検出されるが、この成分については消音用
ディジタルフィルタ２から加算点２０までの伝送特性を
再現したディジタルフィルタ２２の出力信号を逆位相に
してセンサマイクロフォンＭ１の出力信号と加算点２０
により加算することにより打ち消されるのでスピーカＳ
からセンサマイクロフォンＭ１への音響的フィードバッ
クは抑制される。すなわち、ディジタルフィルタ２２は
音響的フィードバック抑制のためのディジタルフィルタ
として作用する。Incidentally, the sound wave for muffling from the speaker S is detected by the sensor microphone M1, but for this component, the output signal of the digital filter 22 that reproduces the transmission characteristics from the digital filter for muffling 2 to the addition point 20 is reverse-phased. Output signal of sensor microphone M1 and addition point 20
Since it is canceled by adding
Acoustic feedback from the sensor microphone M1 to the sensor microphone M1 is suppressed. That is, the digital filter 22 acts as a digital filter for suppressing acoustic feedback.

第１図に示した電子消音システムのモデルを示す第２図
においてＧはセンサマイクロフォンＭｌ。In FIG. 2, which shows a model of the electronic silencing system shown in FIG. 1, G is a sensor microphone Ml.

Ｍ２の間の伝搬通路１内における音波の伝搬特性及びセ
ンサマイクロフォンＭ　１　、　Ｍ　２の変換特性を加
味した伝達関数、Ｄは既述したようにディジタルフィル
タ２の出力端からエラー信号の加算点まで、換言すれば
ディジタルフィルタ２の出力端からスピーカＳ１スピー
カＳからマイクロフォンＭ２までの伝搬通路及びセンサ
マイクロフォンＸ１２についての各電気音響変換器自体
の変換特性及び音波の伝搬特性を含めた伝送特性を示す
伝達関数である。D is a transfer function that takes into account the propagation characteristics of the sound wave in the propagation path 1 between M2 and the conversion characteristics of the sensor microphones M1 and M2, and D is the transfer function from the output end of the digital filter 2 to the addition point of the error signal, as described above. In other words, the transmission characteristic including the conversion characteristic of each electroacoustic transducer itself and the propagation characteristic of the sound wave regarding the propagation path from the output end of the digital filter 2 to the speaker S1 and the microphone M2 and the sensor microphone X12. It is a function.

次に伝達関数りを考慮した電子消音システムをコントロ
ーラを含めて具体化したモデルを第３図に示す。このモ
デルではコントローラ部１０に適応制御アルゴリズムと
してＶＳ−ＬＭＳアルゴリズムを用い、加算点２０の出
力信号Ｘに伝達関数りを乗じたものをディジタルフィル
タ２の入力信号として捉え、これを用いてディジタルフ
ィルタ２の係数の更新を行う。従ってＶＳ−ＬＭＳアル
ゴリズムによる演算の入力として入力信号ＸをＸ・Ｄに
置換することによってＶＳ−ＬＭＳアルゴリズムによる
フィルタ係数の更新が可能となる。Next, FIG. 3 shows a model that embodies an electronic silencing system including a controller that takes into consideration the transfer function. In this model, the controller unit 10 uses the VS-LMS algorithm as an adaptive control algorithm, and the output signal Update the coefficients. Therefore, by replacing the input signal X with X.D as an input for calculation by the VS-LMS algorithm, it becomes possible to update the filter coefficients by the VS-LMS algorithm.

伝達関数りは後述するようにシステムを稼動する前にコ
ントローラ部１０により求め、伝達関数りを特定するフ
ィルタ係数を決定する。システム稼動時にはこのフィル
タ係数を固定してＶＳ−ＬＭＳアルゴリズムによりディ
ジタルフィルタ２が適応制御される。As will be described later, the transfer function RI is obtained by the controller section 10 before operating the system, and filter coefficients for specifying the transfer function RI are determined. When the system is in operation, the filter coefficients are fixed and the digital filter 2 is adaptively controlled by the VS-LMS algorithm.

第４図には第３図に示すモデルを適用した電子消音シス
テムの具体的構成が示されている。同図において、伝搬
通路１内にはセンサマイクロフォンＭｌ、Ｍ２が付加音
源たるスピーカＳを挟んで配設されている。FIG. 4 shows a specific configuration of an electronic silencing system to which the model shown in FIG. 3 is applied. In the figure, sensor microphones M1 and M2 are arranged in a propagation path 1 with a speaker S serving as an additional sound source sandwiched therebetween.

３０．３２はそれぞれ、マイクロフォンＭ１、Ｍ２の出
力信号を増幅するマイクアンプ、３４はスピーカＳに出
力する駆動信号を所定のレベルまで増幅するパワーアン
プである。30 and 32 are microphone amplifiers that amplify the output signals of the microphones M1 and M2, respectively, and 34 is a power amplifier that amplifies the drive signal output to the speaker S to a predetermined level.

又５０．５２はＡ／Ｄコンバータ、５４はＤ／Ａコンバ
ータ、１０００は制御部である。Further, 50.52 is an A/D converter, 54 is a D/A converter, and 1000 is a control section.

制御部１０００はシステム全体を統括制御するコントロ
ールプロセッサ１００、後述する適応型ディジタルフィ
ルタ、固定係数型ディジタルフィルタ及び既述した伝達
関数りを測定するためのノイズジェネレータとしての役
割を果たすディジタルシグナルプロセッサ１０２．１０
４、直列信号を並列信号に、又は並列信号を直列信号に
変換処理スルンリアル・パラレルインターフェースアダ
プタ１０６．１０８とから構成されており、これらは相
互にパスライン２００を介して接続されている。The control unit 1000 includes a control processor 100 that centrally controls the entire system, a digital signal processor 102 that serves as an adaptive digital filter, a fixed coefficient digital filter, and a noise generator for measuring the transfer function described above. 10
4. A real parallel interface adapter 106, 108 for converting a serial signal into a parallel signal or a parallel signal into a serial signal, and these are connected to each other via a path line 200.

第１図に示した電子消音システムの動作を第５図を参照
して説明する。第５図は制御部１０００の動作をブロッ
ク化して示したものである。同図においてシステムを稼
動させるに先立ち、スイッチ２０８が接点ａ側に切換ら
れ、ノイズジェネレーター２０６よりＤ／Ａコンバータ
５４に擬似ランダムノイズが出力される。The operation of the electronic silencing system shown in FIG. 1 will be explained with reference to FIG. 5. FIG. 5 shows the operation of the control section 1000 in blocks. In the figure, before starting the system, the switch 208 is switched to the contact a side, and the noise generator 206 outputs pseudorandom noise to the D/A converter 54.

他方ディジタルシグナルプロセッサ１０４により適応型
ディジタルフィルタ２１０を構成し、適応型ディジタル
フィルタ２１０はノイズジェネレータ−２０６からの入
力信号（擬似ランダムノイズ）と、センサーマイクロフ
ォンＭ２がらの出力信号であるＡ／Ｄコンバータ５２の
出力信号（工ラー信号〉とに基づいて適応型ディジタル
フィルタ係数更新アルゴリズム実現回路２２０により伝
達関数りを同定する。On the other hand, the digital signal processor 104 constitutes an adaptive digital filter 210, which receives an input signal (pseudo-random noise) from the noise generator 206 and an A/D converter 52 which is an output signal from the sensor microphone M2. Based on the output signal (processor signal), the adaptive digital filter coefficient update algorithm realization circuit 220 identifies the transfer function.

また、同様に適応型ディジクルフィルタ４１０はノイズ
ジェネレーター２０６からの入力信号と、センサーマイ
クロフォンＭ１からの出力信号であるＡ／Ｄコンバータ
５０の出力信号とに基づいて音響フィードバンク抑制用
ディジタルフィルタ２２の伝達関数Ｆを同定する。Similarly, the adaptive digital filter 410 controls the acoustic feedbank suppression digital filter 22 based on the input signal from the noise generator 206 and the output signal of the A/D converter 50, which is the output signal from the sensor microphone M1. Identify the transfer function F.

次いで、スイッチ２０８を接点す側に切換え、電子消音
システムを稼動できる状態にする。次にディジタルフィ
ルタ２１０で同定した伝達関数りを示すフィルタ係数を
ディジタルフィルタ２０２に、同様にディジタルフィル
タ４１０で同定した伝達関数Ｆを示すフィルタ係数Ｆを
ディジタルフィルタ２２に設定する。ディジタルフィル
タ２０２及び２２はディジタルシグナルプロセッサ１０
２が機能分担し、適応型ディジタルフィルタ２０４並び
に適応型ディジタルフィルタ係数更新アルゴリズム実現
回路２２０についてはディジクルシグナルプロセッサ１
０４が機能分担する。この適応型ディジタルフィルタ２
０４は第３図に示したモチ゛ルにおけるディジタルフィ
ルタ２に相当するものである。Next, the switch 208 is switched to the contact side to put the electronic silencing system into a state where it can be operated. Next, a filter coefficient indicating the transfer function F identified by the digital filter 210 is set in the digital filter 202, and a filter coefficient F indicating the transfer function F similarly identified by the digital filter 410 is set in the digital filter 22. The digital filters 202 and 22 are connected to the digital signal processor 10.
The adaptive digital filter 204 and the adaptive digital filter coefficient update algorithm implementation circuit 220 are handled by the digital signal processor 1.
04 will share the functions. This adaptive digital filter 2
04 corresponds to the digital filter 2 in the model shown in FIG.

このような状態下において加算点２０にＡ／Ｄコンバー
タ５０、ディジタルフィルタ２２を介してそれぞれ電気
信号が入力され、該加算点２０においてＡ／Ｄコンバー
タ５０の出力信号とディジタルフィルタ２２の出力信号
を反転した信号とが加算され、更にディジタルフィルタ
２０２において加算点２０の出力信号Ｘとディジタルフ
ィルタ２０２において設定された伝達関数りとの乗算が
行われる。Under such conditions, electrical signals are input to the summing point 20 via the A/D converter 50 and the digital filter 22, and the summing point 20 combines the output signal of the A/D converter 50 and the output signal of the digital filter 22. The inverted signal is added, and the digital filter 202 further multiplies the output signal X of the addition point 20 by the transfer function set in the digital filter 202.

適応型ディジタルフィルタ係数更新アルゴリズム実現回
路２２０はＡ／Ｄコンバータ５２の出力信号をエラー信
号として取り込み、この信号とディジタルフィルタ２０
２の出力Ｘ−Ｄに基づいて適応型ディジタルフィルタ２
０４のフィルタ係数を更新し、適応型ディジタルフィル
タ２０４は加算点２０の出力信号Ｘに対して所定の演算
処理を行い、これをスイッチ２０８を介してＤ／Ａコン
バータ５４にセンサマイクロフォンＭ２の設置位置にお
いて騒音源からの伝搬音波を消去するためのスピーカＳ
の駆動信号として出力する。第５図における加算点２Ｑ
の演算はコントロールプロセッサ１００により行われ、
該コントロールプロセッサ１００はこの他に電子消音シ
ステムと図示していない電子消音システムが適用される
他のシステム例えば空調設備等との間の信号の送受を行
う。The adaptive digital filter coefficient update algorithm implementation circuit 220 takes in the output signal of the A/D converter 52 as an error signal, and uses this signal and the digital filter 20
Adaptive digital filter 2 based on the output X-D of 2
04, the adaptive digital filter 204 performs predetermined arithmetic processing on the output signal Speaker S for canceling propagating sound waves from a noise source in
output as a drive signal. Additional point 2Q in Figure 5
The calculation is performed by the control processor 100,
The control processor 100 also transmits and receives signals between the electronic silencing system and other systems (not shown) to which the electronic silencing system is applied, such as air conditioning equipment.

更にコントロールプロセッサ１００は電子消音システム
の動作を監視し、システムに異常が生じた場合にはそれ
に対応するための処理を行う。この他、消音用ディジタ
ルフィルタ２０４のフィルタ係数更新のＯＮ、ＯＦＦ運
転なども判断出来、これにより、適応制御され不安定な
状況における対応が可能となる。Furthermore, the control processor 100 monitors the operation of the electronic muffling system, and performs processing to deal with any abnormality that occurs in the system. In addition, it is possible to determine whether to update the filter coefficients of the silencing digital filter 204 or not, thereby making it possible to respond to unstable situations through adaptive control.

尚、第２図に示した適応型ディジタルフィルタ２０４．
２１０．４１０においてはＶＳ−ＬＭＳアルゴリズムを
用いたが、これに限らずＢＬＭＳ（Ｂｌｏｃｋ　Ｌｅａ
ｓｔ　Ｍｅａｎ　５ｑｕａｒｅ　）或いはＦ　ＬＭＳ（
Ｆａｓｔ　Ｌｅａｓｔ　Ｍｅａｎ　５ｑｕａｒｅ）等の
適応アルゴリズムを使用してもよい。又、加算点２０は
本実施例ではディジタル演算によって行っているが、デ
ィジタルフィルタ２２共にコントローラの外部に取り出
しアナログ信号の段階で行ってもよい。Note that the adaptive digital filter 204 shown in FIG.
In 210.410, the VS-LMS algorithm was used, but the VS-LMS algorithm is not limited to this.
st Mean 5 square ) or F LMS (
An adaptive algorithm such as Fast Least Mean 5quare) may also be used. Further, although the addition point 20 is performed by digital calculation in this embodiment, the addition point 20 may be taken out of the controller together with the digital filter 22 and performed at the analog signal stage.

さらに第４図に示したシステム構成ではディジクルシグ
ナルプロセッサを２個、コントロールプロセッサを１個
用いることとしているが、高機能なマイクロプロセッサ
を用いてこれにより行うことも可能である。又ディジタ
ルシグナルプロセッサ１０２．１０４等の代わりにそれ
ぞれ高速の乗加算器を用いてもよい。Further, although the system configuration shown in FIG. 4 uses two digital signal processors and one control processor, it is also possible to use a highly functional microprocessor. Also, high-speed multipliers and adders may be used in place of the digital signal processors 102 and 104, respectively.

本発明の適用を、第５図に準じたブロック図による表現
を用いてさらに詳しく説明する。尚、第５図と共通の部
分に関しては同一の符号を付しその説明は省略する。Application of the present invention will be explained in more detail using a block diagram representation according to FIG. Incidentally, parts common to those in FIG. 5 are given the same reference numerals, and explanations thereof will be omitted.

消音の対象が特殊な場合には、電気機械変換手段によっ
て作成された付加音と騒音源からの伝盪信号を検出し電
気信号に変換する第１の機械電気変換手段との間の結合
が疎になるために、音響的なフィードバンクグループを
考慮しなくてもよい場合がある。例えば、振動ピンクア
ップ等の第１の機ｖｉ電気変換手段により音圧てはなく
騒音源の振動速度成分を検出する場合や、第１の機械電
気変換手段が、付加音を発生させる電気機械変換手段か
ら遠方にあるなどの条件のために機構的に疎結合が実現
されている場合等は、第５図に示した入力及び誤差信号
はさらに簡単な構成として実現可能である。最も簡単な
場合は、第６図に示すように騒音検出信号を適応型ディ
ジタルフィルタ２０４０入力信号として直接用いる場合
である。ところがこの場合であっても、本質的に付加音
作成用電気機械変換手段から誤差信号を検出するための
機械電気変換手段との間には時間遅延を含む伝達関数り
が存在するために、第１図に示すような本発明による適
応型ディジタルフィルタ系の適用が高い消音効果を確保
するために必要となる。When the object to be silenced is special, the coupling between the additional sound created by the electromechanical conversion means and the first electromechanical conversion means that detects the transmitted signal from the noise source and converts it into an electric signal is loose. In some cases, it is not necessary to consider acoustic feedbank groups to achieve this. For example, in a case where the first machine vi electrical conversion means such as a vibration pink-up detects the vibration velocity component of a noise source instead of the sound pressure, or when the first mechanical electrical conversion means detects an electromechanical conversion that generates additional sound. In cases where mechanically loose coupling is realized due to conditions such as being located far from the means, the input and error signals shown in FIG. 5 can be realized as an even simpler configuration. The simplest case is when the noise detection signal is directly used as an input signal to the adaptive digital filter 2040, as shown in FIG. However, even in this case, there is essentially a transfer function including a time delay between the electromechanical conversion means for creating the additional sound and the electromechanical conversion means for detecting the error signal. Application of an adaptive digital filter system according to the present invention as shown in FIG. 1 is necessary to ensure a high silencing effect.

また、第１図では音響的フィードバック抑制用のディジ
タルフィルタ２２を固定係数型ディジタルフィルタで構
成したが、適応型ディジタルフィルタであればさらに適
用範囲が広くなるのは周知である。Further, in FIG. 1, the digital filter 22 for suppressing acoustic feedback is configured as a fixed coefficient type digital filter, but it is well known that an adaptive digital filter can be applied to a wider range of applications.

第７図はその具体的構成を示した。Ｅ２２はディジタル
フィルタ２２のエラー信号を、Ｘ２２が入力信号を示し
ている。アダプタコントロール消音用ディジタルフィル
タ２と併用しても、独立していてもよい。FIG. 7 shows its specific configuration. E22 indicates an error signal of the digital filter 22, and X22 indicates an input signal. It may be used together with the adapter control silencing digital filter 2, or may be used independently.

以上述べてきたように、本発明は電子消音システムに限
らず、時間遅延を伴う伝達関数を含む全ての適応制御系
に対応することが可能である。As described above, the present invention is applicable not only to electronic silencing systems but also to all adaptive control systems including transfer functions with time delays.

〔発明の効果〕〔Effect of the invention〕

以上に説明したように本発明に係る電子消音システムで
はシステムを稼動するに先立ち、音波の伝搬通路内に擬
似信号に基づく音波を付加音源としての電気機械変換手
段より放射し、この音波に対して消音効果を評価するた
めの第２の機械電気変換手段の出力信号（エラー信号）
が最小となるように前記電気機械変換手段の駆動信号を
作成する駆動信号作成手段の出力端から第２の機械電気
変換手段に至る音波の伝搬通路及び電気信号の転送路を
含む伝送系の伝送特性を示す時間遅延を伴う伝達関数を
制御手段により特定し、該制御手段がこの特定された時
間遅延を伴う伝達関数を考、慮して所定の適応アルゴリ
ズムに基づいて前記駆動信号作成手段に付与すべき伝達
関数を決定するように構成したので、本発明によれば消
音効果の高い電子消音システムを実現することが可能と
なる。As explained above, in the electronic silencing system according to the present invention, before operating the system, a sound wave based on a pseudo signal is emitted from the electromechanical conversion means as an additional sound source into the sound wave propagation path, and the sound wave is Output signal (error signal) of the second mechanical-electric conversion means for evaluating the silencing effect
A transmission system including a sound wave propagation path and an electrical signal transfer path from the output end of the drive signal generation means to the second electromechanical conversion means to generate a drive signal for the electromechanical conversion means such that A control means specifies a transfer function with a time delay that indicates the characteristic, and the control means takes into account the specified transfer function with a time delay and applies it to the drive signal generation means based on a predetermined adaptive algorithm. Since the present invention is configured to determine the transfer function to be used, it is possible to realize an electronic muffling system with a high muffling effect.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明が適用される電子消音システムの基本構
成を示す原理図、第２図は第１図に示した電子消音シス
テムのモデルを示す説明図、第３図は時間遅れを伴う伝
達関数りを考慮した電子消音システムをコントローラを
含めて具体化したモデルを示す説明図、第４図は第３図
に示すモデルを適用した電子消音システムの具体的構成
を示すブロック図、第５図は第１図に示す電子消音シス
テムの制御部の動作をブロック化して示す説明図、第６
図及び第７図は電子消音システム制御部の変形例を示す
説明図、第８図は従来の電子消音システムの構成図であ
る。 １・・・伝搬通路、　　ｌＯ・・・コントローラ、　　
２０・・・加算点、　３０．３２．３４・・・アンプ、
　　５０・・・Ａ／Ｄコンバータ、　　５４・・・Ｄ／
Ａコンバータ、１００・・・コントロールプロセッサ、
　　１０２．１０４・・・ディジタルングナルプロセッ
サ、　　１０６．１０８・・・ンリアル・パラレルイン
ターフェースアダプタ。Fig. 1 is a principle diagram showing the basic configuration of an electronic silencing system to which the present invention is applied, Fig. 2 is an explanatory diagram showing a model of the electronic silencing system shown in Fig. 1, and Fig. 3 is a transmission with time delay. FIG. 4 is a block diagram showing a specific configuration of an electronic silencing system to which the model shown in FIG. 3 is applied; FIG. 6 is an explanatory diagram showing in block form the operation of the control unit of the electronic silencing system shown in FIG.
7 and 7 are explanatory diagrams showing modified examples of the electronic silencing system control section, and FIG. 8 is a configuration diagram of a conventional electronic silencing system. 1... Propagation path, lO... Controller,
20...addition point, 30.32.34...amplifier,
50...A/D converter, 54...D/
A converter, 100... control processor,
102.104... Digital digital processor, 106.108... Digital parallel interface adapter.

Claims (2)

【特許請求の範囲】[Claims] （１）音波の伝搬通路内に於ける騒音源からの伝搬音波
に対して逆位相で且つ同一音圧の音波を発生させ、前記
伝搬通路内の所定位置でその音波干渉により消音を行う
電子消音システムにおいて、前記伝搬通路内の前記所定
位置より騒音源側に配設され、該騒音源からの伝搬音波
を検出し電気信号に変換する第１の機械電気変換手段と
、前記伝搬通路内に於ける第１の機械電気変換手段の配
設位置と前記所定位置との間に設けられ騒音源からの伝
搬音波を該所定位置において打ち消すための音波を放射
する電気機械変換手段と、該電気機械変換手段の配設位
置と前記所定位置との間又は該所定位置に設けられ、該
電気機械変換手段及び前記騒音源からの伝搬音波を検出
し電気信号に変換する第２の機械電気変換手段と、前記
第１の機械電気変換手段の出力信号と電気機械変換手段
に与える駆動信号又は該駆動信号を入力するディジタル
フィルタの出力信号を取込んで両者の差を求める演算手
段と、 該演算手段の出力信号を取り込み、与えられた伝達関数
に基づいて電子消音システムの消音量が最大になるよう
に前記電気機械変換手段に与える駆動信号を作成する駆
動信号作成手段と、 該駆動信号作成手段に付与すべき伝達関数を決定し、該
伝達関数を特定する為の制御パラメータを駆動信号作成
手段に設定すると共に、伝搬通路の伝搬特性の変化及び
制御系の特性変化に応じて前記制御パラメータを修正す
る制御手段と、を備えたことを特徴とする電子消音シス
テム。(1) Electronic silencing that generates a sound wave with the opposite phase and the same sound pressure as the sound wave propagating from a noise source in a sound wave propagation path, and mutes the sound at a predetermined position in the sound wave interference by the sound wave interference. In the system, a first electromechanical conversion means is disposed closer to the noise source than the predetermined position in the propagation path, and detects a propagating sound wave from the noise source and converts it into an electric signal; an electromechanical transducer that is provided between the location of the first electromechanical transducer and the predetermined position and emits a sound wave for canceling the propagating sound wave from the noise source at the predetermined position, and the electromechanical transducer. a second electromechanical conversion means that is provided between the arrangement position of the means and the predetermined position or at the predetermined position, and detects the propagating sound wave from the electromechanical conversion means and the noise source and converts it into an electric signal; calculation means for taking in the output signal of the first mechanical-electrical conversion means and the drive signal given to the electromechanical conversion means or the output signal of a digital filter inputting the drive signal and calculating the difference between the two; and the output of the calculation means. drive signal generation means for capturing a signal and generating a drive signal to be applied to the electromechanical conversion means so that the amount of silencing of the electronic silencing system is maximized based on a given transfer function; Control that determines a power transfer function, sets control parameters for specifying the transfer function in the drive signal generation means, and corrects the control parameters according to changes in propagation characteristics of the propagation path and changes in characteristics of the control system. An electronic silencing system characterized by comprising means. （２）前記制御手段は、システム起動時に擬似信号を前
記電気機械変換手段に出力して音波の伝搬通路内に音波
を放射し、第２の機械電気変換手段の出力信号に基づい
て該出力信号が最小となるように駆動信号作成手段の出
力端から第２の機械電気変換手段に至る音波の伝搬通路
及び電気信号の伝送路を含む伝送系の伝送特性を示す時
間遅延を伴う伝達関数を特定し、該特定された時間遅延
を伴う伝達関数を考慮して所定の適応アルゴリズムに基
づいて前記駆動信号作成手段に付与すべき伝達関数を決
定することを特徴とする請求項１記載の電子消音システ
ム。(2) The control means outputs a pseudo signal to the electromechanical conversion means to radiate a sound wave into a sound wave propagation path when the system is activated, and outputs a pseudo signal to the electromechanical conversion means based on the output signal of the second electromechanical conversion means. Specify a transfer function with a time delay that indicates the transmission characteristics of the transmission system including the acoustic wave propagation path and the electrical signal transmission path from the output end of the drive signal generation means to the second mechanical-electrical conversion means so that The electronic silencing system according to claim 1, wherein the transfer function to be given to the drive signal generating means is determined based on a predetermined adaptive algorithm in consideration of the specified transfer function with time delay. .
JP63223028A 1988-09-05 1988-09-05 Electronic silencing system Expired - Fee Related JP2598483B2 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
JP63223028A JP2598483B2 (en) 1988-09-05 1988-09-05 Electronic silencing system
US07/313,475 US5018202A (en) 1988-09-05 1989-02-22 Electronic noise attenuation system
GB8904719A GB2222501B (en) 1988-09-05 1989-03-02 Electronic noise attenuation system
DE3908881A DE3908881C2 (en) 1988-09-05 1989-03-17 Active noise reduction system with digital filters
IT8967207A IT1232050B (en) 1988-09-05 1989-03-23 ELECTRONIC NOISE ATTENUATION SYSTEM
FR8903869A FR2636189B1 (en) 1988-09-05 1989-03-23 ELECTRONIC NOISE MITIGATION SYSTEM

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63223028A JP2598483B2 (en) 1988-09-05 1988-09-05 Electronic silencing system

Publications (2)

Publication Number Publication Date
JPH0270195A true JPH0270195A (en) 1990-03-09
JP2598483B2 JP2598483B2 (en) 1997-04-09

Family

ID=16791710

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63223028A Expired - Fee Related JP2598483B2 (en) 1988-09-05 1988-09-05 Electronic silencing system

Country Status (6)

Country Link
US (1) US5018202A (en)
JP (1) JP2598483B2 (en)
DE (1) DE3908881C2 (en)
FR (1) FR2636189B1 (en)
GB (1) GB2222501B (en)
IT (1) IT1232050B (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04254894A (en) * 1990-08-16 1992-09-10 Hughes Aircraft Co Actively adaptive noise erasing device which does not require learning mode
JPH04308899A (en) * 1991-04-05 1992-10-30 Mitsubishi Motors Corp Adaptive active sound elimination system for sound in car
WO1992022054A1 (en) * 1991-05-30 1992-12-10 Fujitsu Ten Limited Noise control apparatus
JPH0525500U (en) * 1991-09-10 1993-04-02 三菱電機株式会社 Active noise control device
DE4432747A1 (en) * 1993-09-17 1995-03-23 Hitachi Medical Corp Magnetic-resonance (nuclear-spin) tomography instrument and method with noise attenuation
US5427102A (en) * 1991-06-21 1995-06-27 Hitachi, Ltd. Active noise cancellation apparatus in MRI apparatus
US5521635A (en) * 1990-07-26 1996-05-28 Mitsubishi Denki Kabushiki Kaisha Voice filter system for a video camera
US5548652A (en) * 1992-03-11 1996-08-20 Mitsubishi Denki Kaibushiki Kaisha Silencing apparatus
JP2017049307A (en) * 2015-08-31 2017-03-09 沖電気工業株式会社 Active noise control device, active noise control program, and active noise control method
US11153472B2 (en) 2005-10-17 2021-10-19 Cutting Edge Vision, LLC Automatic upload of pictures from a camera

Families Citing this family (94)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5293578A (en) * 1989-07-19 1994-03-08 Fujitso Ten Limited Noise reducing device
JP2748626B2 (en) * 1989-12-29 1998-05-13 日産自動車株式会社 Active noise control device
US5125241A (en) * 1990-03-12 1992-06-30 Kabushiki Kaisha Toshiba Refrigerating apparatus having noise attenuation
JP2573389B2 (en) * 1990-03-23 1997-01-22 晴夫 浜田 Electronic silencing method and device
JPH0834647B2 (en) * 1990-06-11 1996-03-29 松下電器産業株式会社 Silencer
EP0465174B1 (en) * 1990-06-29 1996-10-23 Kabushiki Kaisha Toshiba Adaptive active noise cancellation apparatus
IL96710A0 (en) * 1990-07-19 1991-09-16 Booz Allen & Hamilton Inc System and method for predicting signals in real time
JPH06503897A (en) * 1990-09-14 1994-04-28 トッドター、クリス Noise cancellation system
JP3471370B2 (en) * 1991-07-05 2003-12-02 本田技研工業株式会社 Active vibration control device
JPH0519776A (en) * 1991-07-09 1993-01-29 Honda Motor Co Ltd Active vibration controller
JP3089082B2 (en) * 1991-07-10 2000-09-18 シャープ株式会社 Adaptive digital filter
US5809152A (en) * 1991-07-11 1998-09-15 Hitachi, Ltd. Apparatus for reducing noise in a closed space having divergence detector
JP2939017B2 (en) * 1991-08-30 1999-08-25 日産自動車株式会社 Active noise control device
JP2530779B2 (en) * 1991-09-05 1996-09-04 株式会社日立製作所 Noise reduction device
US6850252B1 (en) * 1999-10-05 2005-02-01 Steven M. Hoffberg Intelligent electronic appliance system and method
US5412735A (en) * 1992-02-27 1995-05-02 Central Institute For The Deaf Adaptive noise reduction circuit for a sound reproduction system
US5485523A (en) * 1992-03-17 1996-01-16 Fuji Jukogyo Kabushiki Kaisha Active noise reduction system for automobile compartment
US5347586A (en) * 1992-04-28 1994-09-13 Westinghouse Electric Corporation Adaptive system for controlling noise generated by or emanating from a primary noise source
US5251263A (en) * 1992-05-22 1993-10-05 Andrea Electronics Corporation Adaptive noise cancellation and speech enhancement system and apparatus therefor
EP0578212B1 (en) * 1992-07-07 2000-06-14 Sharp Kabushiki Kaisha Active control apparatus with an adaptive digital filter
US5386689A (en) * 1992-10-13 1995-02-07 Noises Off, Inc. Active gas turbine (jet) engine noise suppression
DE4236155C2 (en) * 1992-10-20 1996-02-08 Gsp Sprachtechnologie Ges Fuer Method and arrangement for active interior noise reduction in vehicles
US5732143A (en) * 1992-10-29 1998-03-24 Andrea Electronics Corp. Noise cancellation apparatus
JPH06149268A (en) * 1992-11-02 1994-05-27 Fuji Heavy Ind Ltd In-cabin noise reducing device
US5613009A (en) * 1992-12-16 1997-03-18 Bridgestone Corporation Method and apparatus for controlling vibration
JPH06242787A (en) * 1993-02-17 1994-09-02 Fujitsu Ltd Sneaking sound control type active noise elimiation device
JP2856625B2 (en) * 1993-03-17 1999-02-10 株式会社東芝 Adaptive active silencer
US5434922A (en) * 1993-04-08 1995-07-18 Miller; Thomas E. Method and apparatus for dynamic sound optimization
US5416845A (en) * 1993-04-27 1995-05-16 Noise Cancellation Technologies, Inc. Single and multiple channel block adaptive methods and apparatus for active sound and vibration control
JP2750084B2 (en) * 1993-05-19 1998-05-13 三星電子株式会社 Noise control device for vacuum cleaner
DE69424419T2 (en) * 1993-06-23 2001-01-04 Noise Cancellation Tech ACTIVE NOISE REDUCTION ARRANGEMENT WITH VARIABLE GAIN AND IMPROVED RESIDUAL NOISE MEASUREMENT
US7103188B1 (en) 1993-06-23 2006-09-05 Owen Jones Variable gain active noise cancelling system with improved residual noise sensing
DE4321352C2 (en) * 1993-06-26 2001-09-13 Mann & Hummel Filter Method for determining a noise signal from a total noise for noise attenuation
DE4408278A1 (en) * 1994-03-11 1995-09-14 Gaggenau Werke Extractor hood with at least partial cancellation of the fan noise
US5546467A (en) * 1994-03-14 1996-08-13 Noise Cancellation Technologies, Inc. Active noise attenuated DSP Unit
JP2899205B2 (en) * 1994-03-16 1999-06-02 本田技研工業株式会社 Active vibration noise control device for vehicles
JP3099217B2 (en) * 1994-04-28 2000-10-16 株式会社ユニシアジェックス Active noise control system for automobiles
WO1996002910A1 (en) * 1994-07-15 1996-02-01 Noise Cancellation Technologies, Inc. Active duct silencer kit
US6201872B1 (en) 1995-03-12 2001-03-13 Hersh Acoustical Engineering, Inc. Active control source cancellation and active control Helmholtz resonator absorption of axial fan rotor-stator interaction noise
JPH08246969A (en) * 1995-03-15 1996-09-24 Unisia Jecs Corp Active noise control device for automobile
EP1074971B1 (en) * 1995-07-03 2003-04-09 National Research Council Of Canada Digital feed-forward active noise control system
US5852667A (en) * 1995-07-03 1998-12-22 Pan; Jianhua Digital feed-forward active noise control system
DE19526098C1 (en) * 1995-07-18 1996-09-12 Stn Atlas Elektronik Gmbh Active sound-dampening equipment
US5715320A (en) * 1995-08-21 1998-02-03 Digisonix, Inc. Active adaptive selective control system
US6198828B1 (en) * 1996-12-17 2001-03-06 Texas Instruments Incorporated Off-line feedback path modeling circuitry and method for off-line feedback path modeling
US5991418A (en) * 1996-12-17 1999-11-23 Texas Instruments Incorporated Off-line path modeling circuitry and method for off-line feedback path modeling and off-line secondary path modeling
US6418227B1 (en) * 1996-12-17 2002-07-09 Texas Instruments Incorporated Active noise control system and method for on-line feedback path modeling
US6658648B1 (en) * 1997-09-16 2003-12-02 Microsoft Corporation Method and system for controlling the improving of a program layout
US6549627B1 (en) * 1998-01-30 2003-04-15 Telefonaktiebolaget Lm Ericsson Generating calibration signals for an adaptive beamformer
DE19832517C2 (en) * 1998-07-20 2003-03-20 Ibs Ingenieurbuero Fuer Schall Active silencing methods and silencers therefor
US6363345B1 (en) 1999-02-18 2002-03-26 Andrea Electronics Corporation System, method and apparatus for cancelling noise
US6594367B1 (en) 1999-10-25 2003-07-15 Andrea Electronics Corporation Super directional beamforming design and implementation
GB9926563D0 (en) * 1999-11-10 2000-01-12 Univ Southampton Optimal controllers and adaptive controllers for multichannel feedforward control of stochastic disturbances
US20040125962A1 (en) * 2000-04-14 2004-07-01 Markus Christoph Method and apparatus for dynamic sound optimization
DE10018666A1 (en) 2000-04-14 2001-10-18 Harman Audio Electronic Sys Dynamic sound optimization in the interior of a motor vehicle or similar noisy environment, a monitoring signal is split into desired-signal and noise-signal components which are used for signal adjustment
US6879922B2 (en) * 2001-09-19 2005-04-12 General Electric Company Systems and methods for suppressing pressure waves using corrective signal
JP2004038428A (en) * 2002-07-02 2004-02-05 Yamatake Corp Method for generating model to be controlled, method for adjusting control parameter, program for generating the model, and program for adjusting the parameter
DE602004004242T2 (en) * 2004-03-19 2008-06-05 Harman Becker Automotive Systems Gmbh System and method for improving an audio signal
EP1833163B1 (en) * 2004-07-20 2019-12-18 Harman Becker Automotive Systems GmbH Audio enhancement system and method
WO2006024188A1 (en) * 2004-08-31 2006-03-09 Anocsys Ag Method for active noise reduction and a device for carrying out said method
KR100768523B1 (en) * 2005-03-09 2007-10-18 주식회사 휴먼터치소프트 The Active Noise Control Method and Device using the Film Speakers
US8170221B2 (en) * 2005-03-21 2012-05-01 Harman Becker Automotive Systems Gmbh Audio enhancement system and method
DE602005015426D1 (en) 2005-05-04 2009-08-27 Harman Becker Automotive Sys System and method for intensifying audio signals
US20080187147A1 (en) * 2007-02-05 2008-08-07 Berner Miranda S Noise reduction systems and methods
US8077489B2 (en) * 2008-05-15 2011-12-13 Lockheed Martin Corporation System and method of cancelling noise radiated from a switch-mode power converter
DE102008061552A1 (en) * 2008-12-11 2010-07-01 Areva Energietechnik Gmbh Method for reducing noise of electrical transformer, involves determining current operating point of transformer and providing measurement protocol for characterizing operating point dependent behavior of transformer
US8165313B2 (en) * 2009-04-28 2012-04-24 Bose Corporation ANR settings triple-buffering
US8073150B2 (en) * 2009-04-28 2011-12-06 Bose Corporation Dynamically configurable ANR signal processing topology
US8073151B2 (en) * 2009-04-28 2011-12-06 Bose Corporation Dynamically configurable ANR filter block topology
US8090114B2 (en) 2009-04-28 2012-01-03 Bose Corporation Convertible filter
US8184822B2 (en) * 2009-04-28 2012-05-22 Bose Corporation ANR signal processing topology
US8737636B2 (en) 2009-07-10 2014-05-27 Qualcomm Incorporated Systems, methods, apparatus, and computer-readable media for adaptive active noise cancellation
JP4718630B2 (en) * 2009-09-14 2011-07-06 シャープ株式会社 Air conditioner operation noise control method
US8669871B2 (en) * 2009-11-13 2014-03-11 University Of Central Florida Research Foundation, Inc. Implementation of on-off passive wireless surface acoustic wave sensor using coding and switching techniques
US8908877B2 (en) 2010-12-03 2014-12-09 Cirrus Logic, Inc. Ear-coupling detection and adjustment of adaptive response in noise-canceling in personal audio devices
WO2012075343A2 (en) 2010-12-03 2012-06-07 Cirrus Logic, Inc. Oversight control of an adaptive noise canceler in a personal audio device
US8737634B2 (en) 2011-03-18 2014-05-27 The United States Of America As Represented By The Secretary Of The Navy Wide area noise cancellation system and method
US8948407B2 (en) * 2011-06-03 2015-02-03 Cirrus Logic, Inc. Bandlimiting anti-noise in personal audio devices having adaptive noise cancellation (ANC)
US9824677B2 (en) 2011-06-03 2017-11-21 Cirrus Logic, Inc. Bandlimiting anti-noise in personal audio devices having adaptive noise cancellation (ANC)
US8958571B2 (en) 2011-06-03 2015-02-17 Cirrus Logic, Inc. MIC covering detection in personal audio devices
US9318094B2 (en) 2011-06-03 2016-04-19 Cirrus Logic, Inc. Adaptive noise canceling architecture for a personal audio device
US9325821B1 (en) 2011-09-30 2016-04-26 Cirrus Logic, Inc. Sidetone management in an adaptive noise canceling (ANC) system including secondary path modeling
US9318090B2 (en) 2012-05-10 2016-04-19 Cirrus Logic, Inc. Downlink tone detection and adaptation of a secondary path response model in an adaptive noise canceling system
US9123321B2 (en) 2012-05-10 2015-09-01 Cirrus Logic, Inc. Sequenced adaptation of anti-noise generator response and secondary path response in an adaptive noise canceling system
US9319781B2 (en) 2012-05-10 2016-04-19 Cirrus Logic, Inc. Frequency and direction-dependent ambient sound handling in personal audio devices having adaptive noise cancellation (ANC)
US9532139B1 (en) 2012-09-14 2016-12-27 Cirrus Logic, Inc. Dual-microphone frequency amplitude response self-calibration
US9369798B1 (en) 2013-03-12 2016-06-14 Cirrus Logic, Inc. Internal dynamic range control in an adaptive noise cancellation (ANC) system
US9414150B2 (en) 2013-03-14 2016-08-09 Cirrus Logic, Inc. Low-latency multi-driver adaptive noise canceling (ANC) system for a personal audio device
US9502020B1 (en) 2013-03-15 2016-11-22 Cirrus Logic, Inc. Robust adaptive noise canceling (ANC) in a personal audio device
US9578432B1 (en) 2013-04-24 2017-02-21 Cirrus Logic, Inc. Metric and tool to evaluate secondary path design in adaptive noise cancellation systems
US9369557B2 (en) 2014-03-05 2016-06-14 Cirrus Logic, Inc. Frequency-dependent sidetone calibration
US9319784B2 (en) 2014-04-14 2016-04-19 Cirrus Logic, Inc. Frequency-shaped noise-based adaptation of secondary path adaptive response in noise-canceling personal audio devices
US10371171B2 (en) * 2014-09-22 2019-08-06 Regal Beloit America, Inc. System and methods for reducing noise in an air moving system
KR20180044324A (en) 2015-08-20 2018-05-02 시러스 로직 인터내셔널 세미컨덕터 리미티드 A feedback adaptive noise cancellation (ANC) controller and a method having a feedback response partially provided by a fixed response filter

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5797987A (en) * 1980-12-06 1982-06-17 Kojima Seisakusho Kk Slide type vertical drain pipe joint device with joining opening to horizontal branch pipe
JPS5797989A (en) * 1980-12-05 1982-06-17 Lord Corp Active sound damper
JPS62119412U (en) * 1986-01-20 1987-07-29
JPS62193310A (en) * 1986-02-11 1987-08-25 ネルソン　インダストリ−ズ　インコ−ポレイテツド Apparatus and method for active attenuation

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2097629B (en) * 1981-04-15 1984-09-26 Nat Res Dev Methods and apparatus for active sound control
JPS59133595A (en) * 1982-11-26 1984-07-31 ロ−ド・コ−ポレ−シヨン Active sound attenuator
GB8404494D0 (en) * 1984-02-21 1984-03-28 Swinbanks M A Attenuation of sound waves
US4677677A (en) * 1985-09-19 1987-06-30 Nelson Industries Inc. Active sound attenuation system with on-line adaptive feedback cancellation
US4736431A (en) * 1986-10-23 1988-04-05 Nelson Industries, Inc. Active attenuation system with increased dynamic range

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5797989A (en) * 1980-12-05 1982-06-17 Lord Corp Active sound damper
JPS5797987A (en) * 1980-12-06 1982-06-17 Kojima Seisakusho Kk Slide type vertical drain pipe joint device with joining opening to horizontal branch pipe
JPS62119412U (en) * 1986-01-20 1987-07-29
JPS62193310A (en) * 1986-02-11 1987-08-25 ネルソン　インダストリ−ズ　インコ−ポレイテツド Apparatus and method for active attenuation

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5579046A (en) * 1990-07-26 1996-11-26 Mitsubishi Denki Kabushiki Kaisha Voice filter system for a video camera
US5548335A (en) * 1990-07-26 1996-08-20 Mitsubishi Denki Kabushiki Kaisha Dual directional microphone video camera having operator voice cancellation and control
US5521635A (en) * 1990-07-26 1996-05-28 Mitsubishi Denki Kabushiki Kaisha Voice filter system for a video camera
JPH04254894A (en) * 1990-08-16 1992-09-10 Hughes Aircraft Co Actively adaptive noise erasing device which does not require learning mode
JPH04308899A (en) * 1991-04-05 1992-10-30 Mitsubishi Motors Corp Adaptive active sound elimination system for sound in car
WO1992022054A1 (en) * 1991-05-30 1992-12-10 Fujitsu Ten Limited Noise control apparatus
US5427102A (en) * 1991-06-21 1995-06-27 Hitachi, Ltd. Active noise cancellation apparatus in MRI apparatus
JPH0525500U (en) * 1991-09-10 1993-04-02 三菱電機株式会社 Active noise control device
US5548652A (en) * 1992-03-11 1996-08-20 Mitsubishi Denki Kaibushiki Kaisha Silencing apparatus
US5617026A (en) * 1993-09-17 1997-04-01 Hitachi Medical Corporation Quiet magnetic resonance imaging apparatus
DE4432747A1 (en) * 1993-09-17 1995-03-23 Hitachi Medical Corp Magnetic-resonance (nuclear-spin) tomography instrument and method with noise attenuation
US11153472B2 (en) 2005-10-17 2021-10-19 Cutting Edge Vision, LLC Automatic upload of pictures from a camera
US11818458B2 (en) 2005-10-17 2023-11-14 Cutting Edge Vision, LLC Camera touchpad
JP2017049307A (en) * 2015-08-31 2017-03-09 沖電気工業株式会社 Active noise control device, active noise control program, and active noise control method

Also Published As

Publication number Publication date
IT8967207A0 (en) 1989-03-23
FR2636189B1 (en) 1994-05-13
GB2222501A (en) 1990-03-07
DE3908881C2 (en) 2001-09-20
US5018202A (en) 1991-05-21
JP2598483B2 (en) 1997-04-09
IT1232050B (en) 1992-01-23
FR2636189A1 (en) 1990-03-09
DE3908881A1 (en) 1990-03-08
GB8904719D0 (en) 1989-04-12
GB2222501B (en) 1992-12-09

Similar Documents

Publication Publication Date Title
JPH0270195A (en) Electronic noise silencing system
JPH0526200B2 (en)
JPS63311396A (en) Electronic muffling system
JPH0574835B2 (en)
JP5164588B2 (en) Active silencer system
JPH0336897A (en) Electronic silencing system
JP3446242B2 (en) Active silencer
JPS621156A (en) Electronic noise eliminating system
JP2620050B2 (en) Active noise control system speaker device
JP2544900B2 (en) Sound emission radiating device for active noise control system
JPH0313998A (en) Electronic sound deadening system
JP3445295B2 (en) Active silencer
JPH09198054A (en) Noise cancel device
JPH0313997A (en) Electronic sound deadening system
JP3332162B2 (en) Active silencer
JP4298865B2 (en) Active silencer system
JPH09106290A (en) Active noise controller
JPH0614009Y2 (en) Active canceller system
JPH06308974A (en) Active muffler
JPH0619784Y2 (en) Active canceller system for intake and exhaust pipes
JP2541020B2 (en) Muffler for radiated noise in openings
JPH07334174A (en) Speaker installing device of active noise control system.
JPH06332468A (en) Active silencer
JPH07334168A (en) Active noise control system
JP2934794B2 (en) Active cancel muffler

Legal Events

Date Code Title Description
S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

LAPS Cancellation because of no payment of annual fees